There is a strong push to reduce chemical residues in ornamentals. Consumers and retailers demand more sustainably produced flowers and plants. Biobest contributes by developing biological strategies for crop protection on a crop by crop basis. “We are constantly looking for new systems to enhance the sustainability of our production,” says Edwin Scholtes, who runs the family business together with his brother Ronald.
R&D delivers new solution
Biobest conducted years of research to achieve efficient control of whitefly and thrips – the two main pests in roses. End 2013, this led to the development of a predatory mite strategy in which the beneficial Euseius gallicus plays a central role.
Edwin started introducing gallicus in the greenhouse early 2015. Just after the introduction, he started blowing Nutrimite, the food supplement for predatory mites developed by Biobest. “The predatory mite population developed very rapidly. The predator colonised the entire 3.7 ha greenhouse within six weeks. New introductions of gallicus were not necessary. It was quite impressive to see so many predatory mites, all of them actively looking for prey in the rose crop.”
Richard van Spronsen, horticulture advisor of Van Iperen, Marcel Verbeek, advisor of Biobest Netherlands, and Juliette Pijnakker, researcher of Biobest Belgium, have assisted the Scholtes brothers during the introduction of the new predatory mite strategy. Juliette explains: “Today, rose growers use mostly Amblyseius swirskii and A. cucumeris, but swirskii struggles to settle and cucumeris must often be introduced again. Gallicus, on the other hand, develops explosively and settles for the long term with the help of Nutrimite. It attacks thrips, whitefly as well as spider mites.”
“Gallicus is a broad-spectrum guardian for my roses,” says Edwin. “Whitefly and spider mites remained at a very low level all year long. In the summer, I found the thrips pressure too high and we had to correct it. This was also the case with other predatory mite strategies. But, thanks to gallicus, we could limit this to five sprayings. Now that the summer is over, we introduced extra gallicus. I am confident that I will go through the winter without spraying and that the predatory mites may even survive until next year.”